1. Field of the Invention
The present invention relates to a balancer of an engine arranged to reduce vibrations of the engine, an engine including the balancer, and an outboard motor including the engine.
2. Description of the Related Art
An engine according to a prior art is disclosed in Japanese Published Unexamined Patent Application No. 2002-21933. The prior art engine includes a reciprocating balancer piston which reciprocates so as to reduce vibrations caused by reciprocal motion of a drive piston. In detail, the engine includes a drive piston, a balancer piston, a crankshaft to be driven to rotate according to reciprocal motion of the drive piston, and a cylinder having a cylindrical shape which houses the balancer piston and includes an opening provided in an end portion. The engine further includes a rod which is joined to the crankshaft and arranged to reciprocate while rocking according to the rotation of the crankshaft, and a joint pin attached to the balancer piston and the rod from the lateral side. The balancer piston is arranged on the side opposite to the drive piston with respect to the crankshaft. The balancer piston is arranged to pivot around the joint pin with respect to the rod. When the rod reciprocates while rocking according to the rotation of the crankshaft, the balancer piston reciprocates inside the cylinder. Vibrations caused by reciprocal motion of the drive piston are canceled by vibrations caused by reciprocal motion of the balancer piston.